Drill 8 · Reading & Writing · Hard Command of Evidence
SAT Reading & Writing: Hard Command of Evidence (Drill 8) is a Reading & Writing practice drill covering Hard Command of Evidence. It contains 5 original questions created by Brian Stewart, a Barron's test prep author with over 20 years of tutoring experience.
Five hard Command of Evidence questions drawing on new findings, two data displays, and a passage from a classic novel. Each wrong choice is plausible but covers only part of the claim or matches the topic while missing the relationship. Decide what the evidence has to show, then find the one choice that shows all of it.
A wild plant grows both in warm southern valleys and in cold northern mountains. The northern populations survive hard frosts that kill the southern ones, and they carry a version of a particular gene that the southern plants lack. Botanists proposed that this gene version is what lets the northern plants survive frost, by helping their cells resist freezing. They wanted to rule out the possibility that the northern plants are simply hardier overall for unrelated reasons.
Question 1. Which finding, if true, would most directly support the botanists' proposal?
Explanation: Choice A is the best answer because the proposal is that this gene version causes the frost survival, so the evidence must isolate the gene from any general hardiness. Southern plants given the northern gene version then surviving frosts that kill unaltered southern plants holds the rest of the plant constant and varies only the gene, which is the exact mechanism proposed. Choice B is wrong because a shorter, more compact form does not show the gene version is what lets the northern plants survive frost. Choice C is wrong because more frost in the north explains why the trait would be useful there but not that this gene produces it. Choice D is wrong because the gene version turning up in other cold-region species does not establish that it causes frost survival in this plant.
In Frankenstein (1818) by Mary Shelley, a student argues that when the creature confronts Victor, he does not claim to be evil by nature; instead he insists that his cruelty springs entirely from his misery, and that being made happy would restore his original goodness.
Question 2. Which quotation from "Frankenstein" most effectively illustrates the student's argument?
Explanation: Choice D is the best answer because the argument has two parts: the creature blames his cruelty on his misery, and he ties a return to goodness to being made happy. The keyed excerpt joins both, saying misery made him a fiend and that being made happy would make him virtuous again. Choice A is wrong because asking for a companion as deformed as himself expresses his loneliness but not that misery caused his cruelty or that happiness would restore his goodness. Choice B is wrong because this names his exclusion and that misery made him a fiend but stops short of the claim that being made happy would make him good again. Choice C is wrong because the comparison to Adam and the fallen angel voices his sense of unjust rejection, a different idea than misery causing his cruelty.
Four Candidate Alloys for a Lightweight Bracket
| Alloy | Strength (MPa) | Density (g/cm3) |
|---|---|---|
| Alloy J | 310 | 2.9 |
| Alloy K | 260 | 2.4 |
| Alloy L | 340 | 3.3 |
| Alloy M | 300 | 2.7 |
An engineer needs the lightest alloy for a bracket, but the part will fail unless the alloy's strength is at least 290 megapascals. Treating any alloy below that strength as unusable, the engineer concluded that the best choice is ________
Question 3. Which choice most effectively uses data from the table to complete the statement?
Explanation: Choice A is the best answer because the engineer first rules out any alloy below 290 megapascals, then takes the lightest of the rest. Alloys J, L, and M clear the threshold while K at 260 does not; among the three that qualify, Alloy M is the lightest at 2.7, so it is the best choice. Choice B is wrong because Alloy K is the lightest overall but its strength of 260 falls below the 290 requirement, so it is unusable. Choice C is wrong because Alloy L is the strongest but also the heaviest of the qualifying alloys, the opposite of what is wanted. Choice D is wrong because Alloy J qualifies and beats Alloy L on weight, but Alloy M qualifies too and is lighter than J, so J is not the lightest.
An outbreak of stomach illness swept through a town. Investigators noted that most of the sick had recently eaten at a popular festival, and concluded that food served at the festival caused the outbreak, proposing that something in the festival food was contaminated. They based this on how many of the patients had attended.
Question 4. Which finding, if true, would most directly weaken the investigators' conclusion?
Explanation: Choice D is the best answer because the conclusion blames the festival food, so a finding that among people who ate the same foods illness tracked the tap water, with water drinkers falling ill and bottled-water drinkers staying well, holds the food constant and points to the water as the cause, undercutting the food explanation. Choice A is wrong because many vendors and foods leaves the festival food as the suspected source and does not challenge that conclusion. Choice B is wrong because a few non-attendees with a separate, unrelated illness says nothing about what caused the festival outbreak and does not point away from the food. Choice C is wrong because where the festival has been held over the years is a background detail that offers no competing cause for this outbreak.
Acousticians measured how the sound level of a steady tone fell with distance from the source in two rooms: one with bare hard walls and floor, and one carpeted and curtained. They concluded that the carpeted room loses sound far faster with distance than the bare room, reasoning that soft surfaces absorb sound that hard surfaces would reflect back. They needed the data to show not just that the sound level drops with distance, but that it drops much more steeply in the carpeted room.
Question 5. Which choice best describes data from the graph that support the acousticians' conclusion?
Explanation: Choice C is the best answer because the conclusion compares how fast sound falls with distance in the two rooms, so the evidence must contrast the two slopes. The graph shows the bare room easing down only from about 82 to 67 decibels across the range while the carpeted room plunges from about 82 to 41, a far steeper drop, which is the contrast the claim rests on. Choice A is wrong because the two rooms starting at the same level up close is true but says nothing about how steeply sound falls with distance. Choice B is wrong because a single farthest-distance comparison shows the carpeted room is lower at one point but not that it declines more steeply across distance. Choice D is wrong because describing only the bare room's level at the far end never sets the two slopes side by side, which is the whole point.